Variable-speed power-transmission



0. S. PULLIAM. VARIABLE SPEED POWER TRANSMISSION.

APPLICATION FILED AUG-7| 1919.

Patented Aug. 23, 1921.

IIWENTOR' QSE/fi'a fi,

A TTORNEYS Be it known that I, OswALn' UNITED STATES OBWALD S. PULLIAI,

PATENT .orslca.

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vnmm-srm rom'rmsmsrom To all whom it may concern." S. PULLIAM, a citizenof the United States, and a resident of the city of New York, borough ofManhattan, in the county and State of New York, have invented a new andImproved.

Variable Speed Power Transmission, of

which the following is a full, clear, andexact description. l

The present invention relates to new and useful improvements in powertransmission devices, and it pertains more particularly to a drivingmechanism adapted for use in selfpropelled vehicles.

The primary object of the present invention' isto provide means by whichthe differential mechanism so commonly employed may be eliminated.

further object of the invention is to provide a device which will notonly replace the differential mechanism heretofore .referred to, but isalso capable of providing for a change of driving speeds, thuseliminating the necessity of the transmission mechanism usually employedin motor vehicles. 1

A still further object of the invention is to so construct a device ofthis character that a wide rangeof speeds maybe obtained.

With the above and other objects in view, reference is had totheaccompanying drawin s in which igure 1 is a horizontal sectional view ofthe mechanism constructed in accordance with the present invention;

Fig. 2 is a sectional view on the line 22 of Fig. 1.

Referring more particularly to the drawings, the reference character 5designates the rear axle of a self-propelled vehicle, upon the oppositeends of WhlCh are mounted the rear traction wheels, which in the presentinstance have not been shown. The reference character 6 designates thepower shaft, and 7 designates its housing, the housing for the rear axle5 being designated by the reference character 8. The rear axle casing 8carries a suitable anti-friction bearing 9, in which the rear end of thepropeller shaft 6 is mounted for rotation, and carried by the rear endof said propeller shaft 6 and rotatable therewith is a bevel gear orpinion 10. The reference character 11 designates a suitableanti-friction bearing, which is supported by means of a web 12, in ahousing 13, which latter is supported in any suitable manner b the axlehousing 8. Suitably ro- Keyed to the axle 5,-as at 2O, is'a bevel gearorpinion 21, and said bevel gear or pinion 21, is adapted to mesh withthe bevel ears or p nions 19, as shown in Fig. 1. ose'ly mounted ontheaxle 5, is a bevel gear 22, which is adapted to engage the smallbevelgears or pinlons at points diametricall -ment wit e bevel gear 21,and said vel gear 22 is provided with a hub extension 23.

The reference character 24 designates a bracket rigidly secured by meansof rivets or the like 25, to the inner face of one of the houslngs 8,and pivotally mounted on said bracket of an operating arm or lever 26,to one end of which is attached a suitable operating mechanism 27 whichin the present instance is in the form of a rigid rod adapted to PIOJGCtforwardly of the machine in prox- 1m1ty to the drivers seat. Pivotallysecured, as at 28, at one end, and at 29 at its opposite end, to thelever 26, is a flexible band 30, and said flexible band 30 is ada ted topass around the hub extension 23 o the bevel gear or pinion 22.

By this construction, it will be seen that upon operation of the lever.26 through the medium of its operating mechanism 27, the flexible band30 may be caused to grip the hub extension 23 of the bevel gear orpinion 22, to retard the same in its movement about theaxle 5.

The operation of the device is as follows:

Power is communicated to the gear wheel 14 by means of the pro llershaft 6, and the annular teeth 15. f the flexible band 30 be slack aboutthe hub extension 23 of the bevel gear or pinion 22, it will be seenthat the resistance offered by the traction wheels will permit of the rwheel 14 turning freely about the ax e 5, with the gear 21 remainingstationary and serving as o posite their oints of en e-. J. P filpeolfloatlon of Letters Patent- Patent d A 23 1921.

Application filed Auzultl, 1919. Serial Io. 815,916.

a circular rack about which the bevel gears or pinions 19 travel, itbeing understood that the bevel gear or pinion 22, it will be seen axle5.

If now pressure be exerted to tighten the flexible band 30, it will beseen that as soon as said pressure is sufficient to overcome theresistance offered by the contact of the traction wheels with theground, the bevel r or inion 22 serves as a circular rack a ut which thegear wheel 14 and the bevel gears or pinions 19 rotate, thuscomm'unicatin power to the bevel gear or pinion 21, whic owing to itsbeing keyed to the axle 5, sets up a rotation thereof to drive the car.

It is to be understood that while the bevel gear or pinion 22 isretarded in its rotation about the axle 5, the maximum power is notdelivered to the said axle until sufficient pressure is exerted on theflexible band 30 to actually prevent any rotation of the bevel gear orpinion 22. However, if said bevel gear or pinion 22 is permittedtorotateabout the axle 5, a wide range of speeds is possible, said speeds beingobtained between the points at which the resistance of the vehicle isovercome by the pressure exerted on the hub extension of the gear orpinion 22, and the absolute stopping of said bevel gear or pinion. Bythe foregoing construction, it will be seen that the present inventionprovides means by which great flexibility of power can be obtained, and,at the same time, the device has all of the virtues of a differentialmechanism.

Further, the present invention permits of the use of a continuous rigidrear axle instead of a sectional axle as commonly employed, thus greatlyincreasing the strength 1,sas,aos

and durability of motor vehicle rear constructions.

While in the present instance the ear wheel 14 is shown as loosely menuon the axle 5, it will be readil apparent that suitable clutch devicesma be em. loyed for connecting said gear whee 14 to t e axle in orderthat the drive will be direct from the propeller shaft 6 through thegear 10 and 14 to the axle 5.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

A device of the character described comprising a driving shaft and adriven shaft, a beve gear loosely mounted on the driven shaft, a bevelgear carried b the driving shaft and meshing with the vel gear on thedriven shaft, a second bevel gear loosely mounted on the driven shaft,said last-mentioned bevel gear having a hub extension, a bevel gearkeyed to the driven shaft and interposed with respect to the two looselymounted beve-l gears on the driven shaft, a plurality of idle gearscarried by the firstmentioned loosely mounted gear on the driven shaftand engaging the second-mentioned loosely mounted gear on the drivenshaft and the bevel gear keyed to the driven shaft, and a friction brakeengaging the hub extension of the last-mentioned loosely mounted gearfor retarding the movement thereof and through the medium of thefirstmentioned loosely mounted gear on the driven shaft and the idlegears carried thereby serving to transmit power from the driving shaftto the driven shaft through the bevel gear keyed thereto.

OSWALD S. PULLIAM.

